Means for supporting elements in an electron device



Sept. 8, 1931.

R. HARDING, JR

MEANS FOR SUPPORTING ELEMENTS IN AN ELECTRON DEVICE Filed March 15 5 2 Sheets-Sheet l Sept. 8, 1931. R. HARDING. JR 1,822,731

MEANS FOR SUPPORTING ELEMENTS IN AN ELECTRON DEVICE 2 Sheets-Sheet 2 Filed March 13 I NVENTOR flARQM/G fR BY (1 gm/ 64W ATTORNEY Patented Sept. 8, 1931 UNITED STATES PATENT OFFICE ROBERT HARDING, J 3., OF WHITE PLAINS, NEW

YORK, ASSIGNOR TO ARGTURUS RADIO TUBE COMPANY, OF NEWARK, NEW JERSEY, A CORPORATION OF DELAWARE MEANS FOR SUPPORTING ELEMENTS IN AN ELECTRON DEVICE Application filed March 13, 1930; Serial No. 435,412.

This invention relates to electron devices and particularly to a means for supporting the elements in an electron device to form a unitary element structure.

One of the objects of the invention is to provide a unitary element structure for a vacuum tube or other electron device which may be. assembled entirely independently from the support provided for it.

Another object of the invention is to provide a means to lock in position all of the elements of a vacuum tube by securing two parts of the element structure together.

Another object of the invention is to provide a novel means to support the filament in a unitary vacuum tube element structure.

Another object of the invention is to providea means to maintain a tension upon each leg of a hairpin filament used as a heater for a heater type vacuum tube.

Other objects of the invention and objects relating particularly to the details of construction and to the method of manufacturing and assembling the various parts will be apparent as the description of the invention proceeds.

Several embodiments of the invention have been illustrated in the accompanying drawings in which:

Fig. 1 is a front sectional elevation of one embodiment of the element structure;

Fig. 2 is an enlarged sectional side view of the construction shown in Fig. 1 and taken on the line 22 of that figure;

Fig. 3 is an enlarged plan view of the elements of Fig. 1;

Fig. 4 is an enlarged sectional plan view taken on the line 1-4 of Fig. 1;

Fig. 5 is a sectional front elevation of a modified form of the element unit;

Fig. 6 is a sectional front elevation of still another modified form of the invention; and

Fig. 7 is a plan View of the construction shown in Fig. 5. v

The invention has been illustrated in Fig. 1 in connection with a vacuum tube having an envelope 10, mounted on the usual base 11 which supports the terminals for the tube and a press 12 is formed integral with the envelope for supporting the elements.

The elements comprise an anode 13, a grid 14:, a cathode 15, and a heater 16 for the cathode. The anode 13 is made in two sections. Each part of the anode comprises a semic'ylindrical portion 17 having a flange 18 ex tending longitudinally on each side thereof and beyond the ends thereof. The ends of the flanges 18 are joined by cross members which comprise three joined semi-cylindrical bands 19 and 20, the latter being at the center and being slightly larger in diameter than the two bands 19. The distance between the flanges 18 on the surface of the cross member is, of course, the same distance as the circumference of the semi-cylindrical portion. When the two portions of the anode are placed back to back the flanges 18 of one portion of the anode contact with the flanges 18 of the other portion and the semi-cylindrical portions 17 cooperate to form a cylindrical anode while the semi-cylindrical portions 19 and 20 cooperate to form cylindrical bands for holding insulating members to support the other elements of the tube.

The grid 14 comprises the usual helix of wire wound upon two support rods 21 and at each end of each of the support rods 21 1s provided a cylindrical insulating member 22 having a recess 23 therein to receive the end of the rod 21 and being of such a diameter that it will fit within the cylindrical band formed by the semi-cylindrical members 19. The latter may be provided with small lugs 24 which may be bent over on the outer ends of the insulators to hold them in place.

The cathode is preferably a cylinder of nickel which may be coated on the outside with suitable electron emitting material as is well known in the art. The upper end of the cathode may fit into a cylinder 25 of insulating material which has a recess 26 to receive the cathode and is of such a diameter that it will fit snugly Within the cylindrical band formed by the two semi-cylindrical bands 20. The upper band may also be provided with small lugs 27 which may be bent over upon the cylindrical member v vided in a cylindrical member 29 which in turn adapted to slidably fit within the cylindrical band formed by the members 20 at the lower end of the anode structure. The recess 28 is deep enough to provide a clearance between the bottom thereof and the end: also the insulator 25 but leaving the insulator of the cathode and a spring 30 is provided in this clearance having the same diameteras the cathode.

A slot 31 is provided on the upper insulator 25 just above the recess 26 to receive a small plate 32 having a notch 33 in the center thereof in which the loop end of a hairpin filament 16 is a'dapted to seat. A hole 34 is provided in the insulator between the recess 26 and the top of the insulator. but this hole is smaller in diameter than the inside of the cathode so as to prevent the filament from touching the cathode at this point. With the loop end. of the filament seated in the notch 33 in the plate 32 the legs of the filament pass downwardly through the cathode, the two ends extending out through a hole 35 extending through the insulator 29 from the recess 28. A pair of angular wire supports 36 are mounted in any desired manner in' the lower insulator 29. as by being molded therein, and extend downwardly and at right angles below the hole 35 and are spaced apart to receive the ends of the hairpin filament which may be welded thereto. The hole 35 is somewhat smaller in diameter than the inside of the cathode to prevent the ends of the filament from touching the cathode at its lower end. I

It will be noted from this construction that the filament holds the metal plate 32, the upper insulator 25, the cathode 15, and the lower insulator 29 together and as the spring 30 is interposed between the lower end of the cathode and the bottom of the recess 28 in the insulator 29 it maintains a tension upon the filament. The insulator 29 is free to move with respect to the retaining cylindrical band 20 at the lower end of the anode structure and as the filament expands and contracts this insulator moves up and down upon the end of the cathode and against the tension of the spring 30.

Thus constructed the elements comprise a unitary structure which may be completely held together by the anode. The cathode and filament may be assembled by placing the insulator 25 upon the upper end of the cathode with the plate 32 in place and the insulator 29, with the spring 30 contained in the recess 28, upon the lower end of the cathode, and then inserting the filament with one leg on each side of the plate 32 downwardly through the cathode until the ends protrude through the hole 35 in the insulator 29. Thereupon the insulator is pushed upwardly toward the anodeparts may be placed in vided with the insulators 22,1and the two sitionsecurely' locking the insulators 22 in position and 29 at the lower end of the cathode, free to move within its retaining band.

Thepress 12 may be provided with a pair of sturdy support rods 37, one on each end of the press, upon which the whole element structure may be supported and which may be welded, therefore, to the anode flanges 18.

A short connector 38 may be sealed in the press 12 and may be connected to the cathode by means of a flexible wire 39 which is welded to a strap 40 which, in turn, passes around the lower end of the cathode just above the insulating member. Strap 40 extends outwardly preferably at an angle as indicated in Fig. 4 so that the wire 39 may pass through the space between the band 19 and 20. A short connector 41 may also be sealed in the press 12 and may be connected to one of the grid support rods 21 by means of the flexible wire 42. A pair of connectors 43 may also be welded in the press to be connected to the filament angles 36 by means of the two flexible wires 44. One of the support posts 37 may be connected by means of a wire 45 to the anode terminal 46 at the base of the tube while the grid connector 41 may be connected by means of a wire 47 to the grid terminal 48 at the base of the tube. The cathode connector 38 may be connected by means of a wire 49 to the cathode terminal 50 at the base of the tube and the two filament connectors 43 may be connected by means of wires 51 to the two terminals 52 for the filament.

Thus constructed the vacuum tube is one which may be easily assembled and the parts are simple and inexpensive. W'hen once mounted on the support rods 37 there can be no movement of the elements of the tube with respect to each other because the unit will move as a whole, it at all, due to the flexible connecting wires to all elements but the anode. Attention is drawn to the fact that both legs of the hairpin filament are maintained taut by the spring connection which urges the insulating member at the lower end of the cathode downwardly together with the lower ends of the filament.

A modification of the invention has been illustrated in Fig. 5, in which the anode 13 is made similar to that shown inFig. 1 as are also the grid 14 and the cathode 15. In place of the plate 32 to support the upper end of the filament, however, I provide a wire 53 of the insulator while the V-shaped portion insulator 25 and the ends of the filament are welded todzheangularsupport'wires 36' pro- :vided for that purpose. This heater cathode unit may then be inserted within the grid 14,

the support rods 21 of which have' been proenters the opening at the top for the filament. The lower insulator 54 may be held in place between the two semi-cylindrical members by means of lugs 55 which may be made integral with the semi-cylindrical portions 20 similarly to the lugs 27 provided in the upper end of the anode in Fig} 1. The lower insulator 54 may have a hole 56 extending completely through the insulator and having a diameter to fit the outer diameter of the cathode. An insulating disc 57 may have a pair of filament connectors 58 mounted rigidly therein and to which the ends of the filament 16 may be attached. A spring 59 may be inserted in the hole 56 between the lower end of the cathode and the insulating disc 57 to urge the disc downwardly away from the cathode and thereby put a tension on the filament 16. A second disc 60 of insulating material is preferably provided immediately 11 top of the disc 57 and small enough in diameter to fit within the coils of the spring so that the spring is maintained in position and cannot touch the filament connectors 58. The insulating disc 60. of course, should be cemented to the disc 57 or the two may be made integral if desired.

In this case also the insulator to which the ends of the filament are attached is held in position together with the cathode and upper insulator by the filament itself the upper end of which is anchored to the upper insulater. The anode may be mounted similarly to the construction shown in Fig. 1 and the grid maybe connected by the flexible wire 42 as in the other construction and the cathode may be connected by means of the strap 40 and flexible wire 39 as in the other construction.

A still further modification of the invention is shown in Fig. 6.

In this construction the anode,v grid, and cathode are similar to those shown in Figs. 1 and 5 but the method of supporting the filament and cathode is slightly different. The lower insulator 61 may be provided with an opening 62 to receive the lower end of the cathode. The opening 62 extends only part way through the insulator forming a shoulder 63 upon which the cathode may rest. A recess 63 is provided in the lower side of the insulator member 61 opposite to the opening 62 and circular in shape having a diameter somewhat larger than the opening 62. A hole' 64 connects the opening 62 and the recess 63 and provides a hole through which the filament may pass. An insulating plate 65 somewhat similar to the plate 57 shown in Fig. 5 but slightly larger in diameter may be used, supporting a pair of filament connectors 66 which may be rigidly mounted upon the insulator. A spring 67 may be positioned in the recess 63 bearing at its upper end against the inner end of the recess and at its outer end against the insulating member 65 and the filament 16 may have its ends welded to the support rods 66 attached to the insulator 65. At the upper end of the element unit a yoke 68 may be provided made of flat spring wire shaped in anarc with the ends thereof bent downwardly at an angle as illustrated at 69 and received within the insulators 22a provided to receive the grid support rod 21. The central portion of the yoke 68 may be twisted to present a vertical strip to which a wire 70 may be welded and which may have its lower end bent to form a hook 71 to receive the upper end or loop of the V-shaped filament.

In this construction the cathode is maintained rigidly between the upper insulator 25 and the lower insulator 61. both of these insulators being held within the cylindrical bands 20 by means of the lugs as described in connection with the other figures. The spring 67, bearing as it does against the insulator 61 and against the insulating member 65 urges the lower end of the filament away from the cathode and insulator thereby maintaining a tension upon the filament as will be evident from an inspection of the drawing.

In assembling the construction of both Figures 5 and 6, the filament may have its ends welded to the support wires formed upon the insulator disc and then the loop end may be inserted into the cathode from the bottom thereof after the spring has been placed upon the insulating plate. When the spring has reached its normal position .it is further compressed until the upper end of the filament passes up out of the upper insulator whereupon the connection is made to the loop of the filament by slipping the wire 53.within the loop, in case the construction of Fig. 5 is used, and slipping the hook 71 within the loop in using the construction of Fig. 6.

The same support rods for the connections may be used for the construction shown in Figs. 5 and 6 as was used in Figs. 1 to 4, the whole element unit being supported on the two sturdy support posts 37 which are sealed in the press.

It will be evident from the above description that I have provided a unitary element structure for a vacuum tube in which the elements are rigidly supported with respect to each other and cannot get out of alignment so that the characteristics of the tube cannot possibly change during operation nor can the parts become short circuited. A hairpin filament can be used in this connection without any insulation material whatsoever between it and the cathode and there will be'no danger of the lilainent short circuiting with the cathode because it is maintained under tension and in times.

A feature of the invention is illustrated in alignment at all Figs. 1 and 6 wherein the insulators at the to and bottom of the cathode have openings slightly smaller than the inside diameter of the cathode so as to revent the filament from touching the cat ode at these points. For this reason Figs. 1 and 6 may be preferred over the structure illustrated in Fig. 5.

Also it will be noted in Fig. 6 that the spring 67 for maintaining the tension on the filament is spaced from the filament itself and also from the cathode so that it will receive very little heat from the filament and, therefore, the tension of the spring will be permanent and it cannot be heated sufiiciently to remove the tension therefrom.

Many modifications of the invention may be resorted to without departing from the spirit thereof, and I do not desire, therefore,

to l1m1t myself to what has been shown and described except as such limitations occur in the appended claims:

What I claim and desire to secure by Lettcrs Patent is:

1. In a vacuum tube a tubular cathode, having opposite ends, a filament within said cathode, said filament having opposed parts to be supported, an insulating member at one end of said cathode, means to support said filament at one of said opposed parts upon said insulating member, means to anchor the other of said opposed parts of said filament upon the other end of said cathode, and resilient means to urge said insulating member away from said cathode. I

' 2. In a vacuum t, be a tubular cathode, a filament supported within said cathode, means to support one end of said filament upon the corresponding end of said cathode, an insulating member spaced from the opposite end of said cathode, means upon said insulating member for attaching the corresponding end of said filament, and resilient means to urge said insulating member away from the end of said cathode.

3. In a vacuum tube an. anode comprising two parts, a grid, a support rod for said grid, insulating members upon each end of said support rod, a tubular cathode adjacent said grid, an insulating member upon the end of said cathode and means attached to said anode parts to receive said insulating members when said parts are placed together.

4. In a vacuum tube an anode comprising two parts, each of said parts having a semicylindrical portion, a flange on each side of said portion, said flanges being extended beyond the endsof said semi-cylindrical portions, a plurality of semi-cylindrical portions of smaller diameter than said first semi-cylindrical portion connecting the ends of said flanges, a plurality of cylindrical insulating members adapted to be received by said semi-cylindrical portions of said anode parts when said two parts are put together, and a plurality of vacuum tube elemen supported by said insulators.

5. In a vacuum tube a tubular cathode, an insulating member mounted upon one end of said cathode, a filament mounted within said cathode and spaced from the walls thereof, means to mount said filament at one end upon said insulating member, an insulatin member at the other end of said cathode an slidably mounted with respect thereto, a filament support mounted upon said second insulating member and attached to the corresponding end of said filament, and a spring acting to urge said insulating member away from said cathode.

. 6. In a vacuum tube a tubular cathode, an insulating member mounted upon one end thereof, a filament longitudinallypositioned within'said cathode, means to support one end of said filament upon said lnsulating member, a second insulating member having a recess therein and mounted upon the o posite end of said cathode with said cat ode extending within said recess, the insulator being sli able upon said cathode, a filament support on said insulator, said filament having its corresponding end attached to said support, and a compression sprin between the end of said filament and the ottom of said insulator recess.

7. In a vacuum tube a tubular cathode, an insulating member mounted upon one end of said cathode, a filament support mounted upon said insulator, a V-shaped filament within said cathode and spaced from the walls thereof, the loop of said filament being mounted upon said filamentsupport, an insulator slidably positioned on the opposite end of said cathode, said insulator having a recess to 'receivethe end of said cathode, a pair of filament supports spaced upon said second insulating member and having the ends of said V-shaped filament attached thereto, and a spring within said recess and bearing against the end of said cathode to urge said insulating member away therefrom and maintain said filament under tension.

8. In a vacuum tube a tubular cathode, an

insulating member mounted upon said cathodeat one end, means on said insulating member to receive the loop end of a hairpin filament, an insulating member positioned at the opposite end of said cathode, a third insulating member positioned at the same end of said cathode and spaced from the end thereof, a pair of filament supports mounted upon said third insulating member and having the ends of said filament welded thereto, and a spring between the corresponding end of said cathode and said third insulating member whereby said third insulating, memher is urged away from said cathode and a 'tension is maintained upon said filament.

9. In a vacuum tube a unitary element structureincluding a tubular cathode, means to support a hairpin filament at one end of said cathode, an insulating member spaced from the other end of said cathode, means upon said insulating member to support the free ends of said hairpin filament, and a coiled spring between the end of said cathode and said insulating member,

10. In an electron device a unitary element structure including a tubular cathode, an insulating member attached to one end of said cathode, a filament supporting member mounted on said insulating member and extending over the upper end of said cathode, a hairpin filament extending longitudinally within said cathode and having its loop end resting upon said filament supporting member, an insulating memberspaced from the other end of said cathode, means upon said insulating member to support the free ends of said hairpin filament and a coiled spring between the end of said cathode and said last mentioned insulating member.

11. In an electron device a tubular cathode, a pair of spaced apart insulators having re cesses therein to receivethe ends of said cath -.t

ode and openings therethrough to permit the passage of a filament, a hairpin filament mounted within said cathode and extending longitudinally thereof, means mounted adj acent one of said insulators to support the loop end of said filament, an insulating disc adjacent the other insulating member, means to attach the corresponding end of said hairpin I filament to said insulating disc, and resilient means to urge said insulating disc away from said last mentioned insulating member whereby said filament is maintained under tension.

In testimony whereof, I atfix my si ature.

ROBERT HARDIN JR. 

